1. Field of the Invention
The present invention relates to a method of manufacturing a fluid bearing apparatus and more specifically to a method of manufacturing a fluid bearing apparatus of a spindle motor.
2. Description of the Related Art
Spindle motors arranged to rotate disks are typically installed in hard disk apparatuses and optical disk apparatuses. Such spindle motors include a stationary portion fixed to a housing of the apparatus, and a rotating portion arranged to rotate while supporting the disk(s). The spindle motor is arranged to produce a torque by magnetic flux generated between a stator and a magnet, whereby the rotating portion is caused to rotate with respect to the stationary portion.
The stationary portion and the rotating portion of the spindle motor are joined to each other through a fluid dynamic bearing. A known spindle motor including a fluid dynamic bearing is described, for example, in JP-A 2008-190572. The spindle motor described in JP-A 2008-190572 includes a dynamic pressure bearing including a lubricating oil (see paragraph [0021] and FIG. 1 of JP-A 2008-190572).
In a dynamic pressure bearing of this type, a plated member is sometimes used as a bearing member defining a portion of the dynamic pressure bearing. Also in the spindle motor described in JP-A 2008-190572, a sleeve member defining a portion of the dynamic pressure bearing is plated with nickel (see paragraph of JP-A 2008-190572).
However, a plating process may produce a nodule projecting from a surface of a plating layer and an undulation portion at which a layer thickness of the plating layer is uneven. In the fluid dynamic bearing, a stationary bearing member and a rotating bearing member are arranged opposite to each other with a slight gap intervening therebetween, and a fluid is arranged in this gap. During rotation, a dynamic pressure is produced in the fluid arranged in the gap, so that the rotating bearing member is supported with respect to the stationary bearing member. Therefore, a low degree of dimensional accuracy of any bearing member may hinder production of the dynamic pressure.